1. Field of the Invention
The present invention relates to a motor in which a ball bearing can readily be mounted.
2. Description of the Related Art
Japanese Patent Application Publication No. 05-030701 (JP05-030701A) discloses a motor which comprises a rotor including a shaft, a stator, a pair of ball bearings rotatably supporting both ends of the shaft, and a pair of end brackets each having a bearing hole in which the ball bearing is fitted and mounted on either end of the stator. The pair of ball bearings each include an inner race portion and an outer race portion, and rolling elements disposed between the inner and outer race portions. In this motor, a spring member is disposed between the inner race portion of one of the pair of ball bearings and a rotor member of the rotor and is biased to space apart the inner race portion and the rotor member.
In such a motor, however, slippage or a so-called creep phenomenon occurs between the inner race portion of the ball bearing and the shaft, or the outer race portion of the ball bearing and the end bracket. This phenomenon may damage a portion at which the outer race portion of the ball bearing and the end bracket is fitted with each other.